Cellulose compound.



. atilit-y 'is relatively low.

WILLIAM H.. "WALKER, OF NEWTON, MASSACHUSETTS.

GELLULOSE COMPOUND.

Specification of Letters Patent.

No Drawing. Original application filed October 23, 1905, Serial No.284,077. Divided and this application filed September 12, 1908.

To vall whom it may concern:

Be itknown that I, IVILLIAM H. VALKER, of Newton, county of Middlesex,State of Massachusetts, have invented an Improvement in CelluloseCompounds, of which the following is a specification.

This application is a division of my application Serial No. 284,077,filed October 23,1905;

This invention relates to improvements in organic cellulose esters, asfor example the cellulose esters of the fatty acids, such as celluloseacetate, and particuarly to the dissolving or gelatinizing of theseesters by methods involving the use of new solvents and thereby changingtheir physical condition, resulting inthe product-ion of new and usefulproducts. Heretofore chloroform has been the customary volatile solventemployed for the purpose, although other solvents have been suggested.The halogen substitution products of ethane and especially symmetricaltetrachlorethane or acetylenetetrachlorid are solvents for these estersandwell-adapted for dissolving or gelatinizing cellulose acetate.Acetylene tetrachlorid for example, is a more powerful solvent forcellulose acetate than chloroform and its vol- But in order to obtainthe advantages offered by the use of the halogen substitution productsof ethane and especially acetylene teti'achlorid assolvents forcellulose acetate and at the same time produce a more satisfactorysolution, inasmuch as it will film more quickly, I add thereto a liquidalcoholic ingredient or ingredients which are soluble or miscibletherem, which alone is a non-solvent for the cellulose acetate. Forexample, wood alcohol, when admixed with acetylene tetrachlorid inproper proportions, will not destroy the specific solvent action of thelatter upon cellulose acetate, but give "the added advantage of causingthe solution vto film more quickly than if acetylene tetrachlorid aloneis used. The addition of wood alcohol. in

suitable proportions; to acetylene tetrachlorid produces a mixture whichis an es e-.

cially powerful and useful solvent for cell u Serial N 0. 452,776.

lose acetate in spite of the fact that the wood alcohol alone is not asolvent; in fact the combination of wood alcohol and acetylenetetrachlorid makes a more powerful solvent of cellulose acetate thanacetylene tetrachlorid alone. Thus for example, by dissolving one partof celluose acetate in ten to twelve parts by weight of acetylenetetrachlorid containing one part wood alcohol, a mixture or solutioneminently suitable for varnish or lacquer is obtained which flows easilyand leaves upon evaporation, in thin layers, a smooth, transparent filmor coat.

'It is not necessary in effecting the desired solution that theingredients be mixed together in any particular order, as the celluloseacetate may be first impregnated with the proper quantity of woodalcohol and then with the acetylene tetrachlorid, or the celluloseacetate may be first treated with the acetylene tetrachlorid and thewood alcohol subsequently added.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is 1. A composition of matter, consisting ofcellulose acetate and a mixture of acetylene tetrachlorid and a liquidwhich is soluble or miscible therein, but which alone is a nonsolventfor the cellulose acetate.

2. A composition of matter, consistin of cellulose acetate, and amixture of acety ene tetrachlorid and a liquid alcohol, which alone is anon-solvent for cellulose acetate.

3. A composition of matter consistin of cellulose acetate and a mixtureof acety ene tetrachlorid and wood alcohol.

4. A solvent for organic esters of cellulose, consisting of a halogensubstitution product of ethane, modified by a substance which alone is anon-solvent for the ester.

In testimony whereof, I have signed my name to this specification, inthe presence of two subscribing witnesses.

WILLIAM H. WALKER. Witnesses:

JULIA BASS, I EDITH L. BRETT.

Patented Nov. 21, 1911. I

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